//
// serialstep.ino
//
// serial step-and-direction
//
// Neil Gershenfeld 4/11/21
// Quentin Bolsee 12/7/21 : add button
// Alan Han 04/18/22 : modified for arduino nano
//
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
//

//#define LEDA 4
//#define LEDC 2
#define EN 6
#define DIR 4
#define STEP 3
//#define M1 14
//#define M0 15

#define NSTEPS 1000
#define DELAYHIGH 10
#define DELAYLOW 1000
#define BLINK 100

#define BUTTON 31

void setup() {
   //Serial.begin(9600);
   Serial.begin(115200);

   /*
   digitalWrite(LEDA,HIGH);
   pinMode(LEDA,OUTPUT);
   digitalWrite(LEDC,LOW);
   pinMode(LEDC,OUTPUT);
   */

   digitalWrite(EN,HIGH);
   pinMode(EN,OUTPUT);

   digitalWrite(STEP,LOW);
   pinMode(STEP,OUTPUT);

   digitalWrite(DIR,LOW);
   pinMode(DIR,OUTPUT);

   pinMode(BUTTON, INPUT_PULLUP);
   /*
   // 1 step
   digitalWrite(M0,LOW);
   digitalWrite(M1,LOW);
   pinMode(M0,OUTPUT);
   pinMode(M1,OUTPUT);
   // 1/2 step
   digitalWrite(M0,HIGH);
   digitalWrite(M1,LOW);
   pinMode(M0,OUTPUT);
   pinMode(M1,OUTPUT);
   // 1/8 step
   digitalWrite(M0,HIGH);
   digitalWrite(M1,HIGH);
   pinMode(M0,OUTPUT);
   pinMode(M1,OUTPUT);
   // 1/16 step
   digitalWrite(M1,HIGH);
   pinMode(M0,INPUT);
   pinMode(M1,OUTPUT);
   // 1/32 step
   digitalWrite(M0,LOW);
   pinMode(M0,OUTPUT);
   pinMode(M1,INPUT);
   */
   }

void loop() {
   if (Serial.available()) {
      char c = Serial.read();
      if (c == 'f') {
         digitalWrite(DIR,HIGH);
         digitalWrite(STEP,HIGH);
         delayMicroseconds(2);
         digitalWrite(STEP,LOW);
         }
      else if (c == 'r') {
         digitalWrite(DIR,LOW);
         digitalWrite(STEP,HIGH);
         delayMicroseconds(2);
         digitalWrite(STEP,LOW);
         }
      else if (c == '?') {
         // reply with button value
         int btn = digitalRead(BUTTON);
         Serial.write(btn ? '1' : '0');
         }
      }
   }